1. Field of the Invention
The present invention relates to printers, and more specifically to a method and apparatus for rendering in a printer using bands.
2. Related Art
Printers are often used to print a specified content (received from an external system such as personal computers) on medium such as paper. The content to be printed (for example, a page) is typically specified by page description languages (PDL) such as Postscript (PS) and printer control language (PCL), as is well known in the relevant arts. Printing generally entails converting a page content specified by a PDL to a corresponding bit map. The bit map may then be used to print the content on the desired medium.
A page is often divided into bands. A band generally refers to a rectangular section spanning the entire width of the page. A bit map is generally generated for each band, and the page content for the band is printed using the bit map. All the bands of a page may thus be printed to generate the corresponding page.
To facilitate the generation of a bit map for a band with minimal memory, printers often divide a band into sub-bands. A display list (containing lower level primitives such as trapezoids and lines) is typically generated associated with each sub-band. A bit map for the sub-hand is generated using the display list. The generation of such a bit map is often referred to as rendering. A bit map for the entire band would be generated by rendering all the contained sub-bands.
In general, the approaches generating a page content need to be implemented while potentially meeting several requirements (e.g., memory requirement, throughput performance, etc.). What is therefore needed is a method and apparatus which enables rendering while meeting one or more of such requirements.